SVG
- See Resources for presentations and other media for some of the SVG files on our wiki.
Scalable Vector Graphics (SVG) is a W3C standard for vector artwork or drawings as opposed to bitmap images. An SVG document is a sequence of drawing commands in plain text. When the commands are rendered by a browser or other SVG rendering app, an image will be seen. These sequences of drawing commands take up less space than a bitmap. In addition, the SVG files, being plain text, can be compressed further by tools like gzip or a JFFS2 filesystem (actually most SVG readers will automagically unpack gzip-compressed .svgz files though that's not always true for editors).
Since the OLPC has limited storage, SVG imagery is a major part of the content for the OLPC. SVG is very effective in displaying diagrammatic content on the XO.
Authors of OLPC content should try to use SVG wherever possible.
- Only use bitmaps such as JPEG or PNG where it is not possible to use SVG.
- Prefer SVG to PDF for single-page content images. A link to an SVG file will display in Browse, while a PDFs must be downloaded, saved in the journal, then launched in Read. There are tools to convert PDFs to SVG.
Choosing image formats will help you to understand the differences and how to know which format will be best for the intended use. See also Making SVG icons for Sugar!
More info can be found on Wikipedia.
Tools
- Inkscape
- This is an open source drawing program that supports much of the SVG standard. The project goal is to have complete support for SVG, XML and CSS. Extensions for Inkscape can be written in Python so application developers may be able to make creative use of this in developing educational software.
- Flash converter
- If you have artwork in Flash format, you can convert it to SVG using this online converter or this tool whose source is available from the Files tab in the documentation.
Other programs that can output SVG
- chemtool
- 2D chemical structure editor
- FontForge
- Font editor for PS, TrueType and OpenType fonts. It is also a font format converter and can convert among PostScript (ASCII & binary Type 1, some Type 3s, some Type 0s), TrueType, and OpenType (Type2), CID-keyed, SVG, CFF and multiple-master fonts.
- Ploticus
- A Script driven business graphics package
- potrace
- A utility to transform bitmaps into vector graphics
- RLPlot
- GUI based program for displaying scientific data in standard formats.
- Scribus
- Open source desktop page layout program with the aim of producing commercial grade output in PDF and Postscript. SVG vector file output is also provided.
- Skencil
- An interactive vector drawing program
- Xara LX
- Versatile and mature piece of graphics software, tailored for web, print and publishing. Xtreme combines advanced and powerful vector illustration with integrated photo manipulation and DTP features
Since other vector graphics formats can be converted to SVG, many other tools can be used. There are also clipart libraries in SVG format, including the DiaCanvas2 package for Linux, and the Open Clip Art Library.
Sugar activities can be given SVG capabilities with libraries such as python-qt4 (PyQt4), python-biggles and python-pychart.
Free SVG images
The people at freedesktop.org have a lot (~800) of free svg's, released under gpl. To download them with the correct directory-structure, try this script
Many of the images on Wikipedia were uploaded to Wikimedia commons as SVG files. For example http://commons.wikimedia.org/wiki/Image:African_continent-de.svg displays as a PNG at a particular resolution, but the underlying file ( http://upload.wikimedia.org/wikipedia/commons/7/77/African_continent-de.svg at the time of writing) is a scalable SVG.
Resources
- FindTheCountry interactive game in SVG
- http://www.carto.net/papers/svg/samples/canvas.shtml is code to show/hide map layers.
